Re: [Discuss-gnuradio] Analog video modulation.

[Ron Economos]

All video decoders use the YCbCr colorspace. You'll need
to convert that to YIQ for NTSC.

You can create a YCbCr file with vlc.

vlc -I rc <file to decode> -V yuv --yuv-file=<output file> --yuv=chroma=UYVY

This will create a YCbCr file with 4:2:2 chroma in the format
Cb Y Cr Y Cb Y Cr Y .......

vlc does put a header and frame markers in the file. I don't know
if that can be disabled.

YCbCr files only contain the active video (720x480 for NTSC). You'll
have to create and insert the vertical and horizontal blanking.

Ron

On 7/16/2014 6:50 PM, Jordan Johnson wrote:
> After finishing my AM Stereo transmitter, I have decided to build an 
> NTSC modulator. I think I have the actually modulation and filter 
> blocks down, I just need to firgure out how to get the right signals 
> from a digital video file. The file source wouldn't work; I would 
> probably have to use gstreamer. Anyone know exactly what I'm looking 
> for and how to get it? I need brightness, hue, saturation, and I 
> believe that is it.
>
> Thanks.
> - Jordan